11 ms·

From the preliminary report: 'At 500 ft, the FDR indicates: landing gear retracted, slat/flap configuration 3, airspeed 220 knots IAS, descent rate 2000 ft/min

by sitic 6y ago

From the preliminary report: 'At 500 ft, the FDR indicates: landing gear retracted, slat/flap configuration 3, airspeed 220 knots IAS, descent rate 2000 ft/min. According to the FDR and CVR recordings several warnings and alerts such as over-speed, landing gear not down and ground proximity alerts were disregarded. The landing was undertaken with landing gears retracted. The aircraft touched the runway surface on its engines. Flight crew applied reverse engine power and initiated a braking action. Both engines scrubbed the runway at various locations causing damage to both of them. [...]' I'm amazed that the airplane managed to become airborne again despite the engines being dragged down the runway with reverse thrust selected.

VBprogrammer 6y ago
The fact that they where around 80 knots faster than they should have been probably helped a lot. That's a heck of a lot of excess energy.
- craftinator 6y ago
  The excessive speed helped? Can you explain, I would imagine that going faster would cause more engine damage while being dragged.
  - phire 6y ago
    More engine damage, probably. But the excessive speed is what allowed the plane to lift off again.
  - acta_non_verba 6y ago
    But would also mean there was more energy to be converted to lift when the plane increased its attitude to take off again :)
  - VBprogrammer 6y ago
    Helped is probably the wrong word. I mean't that the aircraft had a lot of excess speed to get back into the air again, had it been at a normal approach speed you would probably have slowed down enough that it wouldn't have been possible to get it flying again.
  - ultrarunner 6y ago
    There's a decision point past which your option to abort is no longer viable. Think of an overloaded plane attempting to take off. It may need 400 meters to brake. If the pilot continues to attempt to take off until only 200 meters of runway are left, braking is no longer an option. In the case of the landing attempt above, reverse thrust and the very sketchy (ahem) landing configuration would typically bleed off too much speed to make a successful takeoff possible. Depending on the runway the implicit decision point might have been behind them virtually upon touchdown. With so much excess airspeed, though, while a safe stop was not possible they were still able to fly. It would have been a hell of a ride, though, and just thinking about abusing an airplane like that kind of blows my mind.
- VBprogrammer 6y ago
  From what I can find the Airbus also requires the weight on wheels and the wheels speed sensors to have spun up before it will apply reverse thrust. Obviously the brakes also only work when the wheels are down. Auto-spoilers wouldn't deploy automatically also.
  - valuearb 6y ago
    If I understand correctly does that mean they tried reversers, but they didn’t work so that’s why they initiated a go round?
    - duxup 6y ago
      The initial report indicates they did try to, but many planes won't allow reverse power unless some other indicator (landing gear down an in contact with the ground) says they're on the ground. So maybe they'll go to idle but won't reverse, because reverse while in the air would be bad.
      - rwmj 6y ago
        Fun fact, the Shuttle Training Aircraft actually used reverse thrust in the air to simulate the (probably terrifying) rate of descent of the real thing: https://en.wikipedia.org/wiki/Shuttle_Training_Aircraft https://en.wikipedia.org/wiki/Shuttle_Training_Aircraft
- Diesel555 6y ago
  Pilot here, for anyone confused about the comment... some aircraft reach a speed where it is near a stall and cannot create a positive climb gradient when it touches down. Generally increasing angle of attack (angle the wings are with respect to the airflow) produces more lift. This works until a point is reached where the aircraft stalls (slow speed or high AOA, there is a curve). Many aircraft land near this airspeed, it produces a nice landing. But if you are faster than this airspeed, you can still pull up and create more angle of attack, create more lift, and take back off. So if you are landing fast you can easily pull up. This is exaggerated in fighter aircraft where we land at speeds that are faster than the stall threshold and a drastic pull up at landing can almost always cause a climb.
jessermeyer 6y ago
The pilot was reportedly well seasoned. I have my doubts about the quality of the report given the incredible mishandling of the situation. "Imran Narejo, an official of the PIA Pilots Association, said Gul was a seasoned pilot with 18,000 hours of experience including over 4,000 hours in the A320." https://english.kyodonews.net/news/2020/05/9616e4079ce1-at-least-92-killed-in-plane-crash-in-pakistans-karachi.html https://english.kyodonews.net/news/2020/05/9616e4079ce1-at-l...
- ominous_prime 6y ago
  The report corroborates the witness, video, ADS-B, and ATC recordings we had hours after the crash. It adds more details we couldn’t determine at that time, but otherwise it looks to be quite accurate
- m3h 6y ago
  In Pakistan, there is a culture of becoming overconfident and ignorant of the rules in the airline industry as the pilots age. This was also noted by the Aviation minister when he presented the PIA crash report to the assembly. It should be noted that two of the previous large crashes involving an Airblue and a Bhoja airplane were both concluded to be pilot error with the report pointing to overconfidence and negative attitude in cockpit, in addition to lack of regards for regulations for air safety and lack of training as well.
  - sidewndr46 6y ago
    While I have no doubt this is true of Pakistan, it is true of many people who gain experience in a culture regardless of their age. A while back some US Air Force pilots landed a B-1 bomber on Diego Garcia. The entire flight and the landing was flawless, other than the part where they landed with the gear in the retracted position. The report on the incidents finding was they simply went right past the item on the checklist like it never happened.
  - linuxftw 6y ago
    This is indicative of a systemic culture of rule breaking. This is common in all government run systems. "The system is too arduous, doesn't reflect the 'real world.' We know better than the system, we know what really matters." Eventually you have a bunch of John Waynes playing fast and loose with the rules, eventually they become emboldened, and since the government is famously bad at policing itself, these attitudes are pervasive. This happens at the highest levels, even. Consider Hillary Clinton and the communication of classified (and information that should have been considered classified regardless of markings) via her primary email server. It's a pervasive culture of rule breaking.
AareyBaba 6y ago
This channel has done an excellent job of analyzing the available data [1] https://youtu.be/76osJupy_P8?t=16 https://youtu.be/76osJupy_P8?t=16 and the latest [2] https://youtu.be/xu69Lkf9BYc?t=8 https://youtu.be/xu69Lkf9BYc?t=8

by sitic 6y ago

VBprogrammer 6y ago

The fact that they where around 80 knots faster than they should have been probably helped a lot. That's a heck of a lot of excess energy.

craftinator 6y ago
The excessive speed helped? Can you explain, I would imagine that going faster would cause more engine damage while being dragged.
- phire 6y ago
  More engine damage, probably. But the excessive speed is what allowed the plane to lift off again.
- acta_non_verba 6y ago
  But would also mean there was more energy to be converted to lift when the plane increased its attitude to take off again :)
- VBprogrammer 6y ago
  Helped is probably the wrong word. I mean't that the aircraft had a lot of excess speed to get back into the air again, had it been at a normal approach speed you would probably have slowed down enough that it wouldn't have been possible to get it flying again.
- ultrarunner 6y ago
  There's a decision point past which your option to abort is no longer viable. Think of an overloaded plane attempting to take off. It may need 400 meters to brake. If the pilot continues to attempt to take off until only 200 meters of runway are left, braking is no longer an option. In the case of the landing attempt above, reverse thrust and the very sketchy (ahem) landing configuration would typically bleed off too much speed to make a successful takeoff possible. Depending on the runway the implicit decision point might have been behind them virtually upon touchdown. With so much excess airspeed, though, while a safe stop was not possible they were still able to fly. It would have been a hell of a ride, though, and just thinking about abusing an airplane like that kind of blows my mind.
VBprogrammer 6y ago
From what I can find the Airbus also requires the weight on wheels and the wheels speed sensors to have spun up before it will apply reverse thrust. Obviously the brakes also only work when the wheels are down. Auto-spoilers wouldn't deploy automatically also.
- valuearb 6y ago
  If I understand correctly does that mean they tried reversers, but they didn’t work so that’s why they initiated a go round?
  - duxup 6y ago
    The initial report indicates they did try to, but many planes won't allow reverse power unless some other indicator (landing gear down an in contact with the ground) says they're on the ground. So maybe they'll go to idle but won't reverse, because reverse while in the air would be bad.
    - rwmj 6y ago
      Fun fact, the Shuttle Training Aircraft actually used reverse thrust in the air to simulate the (probably terrifying) rate of descent of the real thing: https://en.wikipedia.org/wiki/Shuttle_Training_Aircraft https://en.wikipedia.org/wiki/Shuttle_Training_Aircraft
Diesel555 6y ago
Pilot here, for anyone confused about the comment... some aircraft reach a speed where it is near a stall and cannot create a positive climb gradient when it touches down. Generally increasing angle of attack (angle the wings are with respect to the airflow) produces more lift. This works until a point is reached where the aircraft stalls (slow speed or high AOA, there is a curve). Many aircraft land near this airspeed, it produces a nice landing. But if you are faster than this airspeed, you can still pull up and create more angle of attack, create more lift, and take back off. So if you are landing fast you can easily pull up. This is exaggerated in fighter aircraft where we land at speeds that are faster than the stall threshold and a drastic pull up at landing can almost always cause a climb.

jessermeyer 6y ago

The pilot was reportedly well seasoned. I have my doubts about the quality of the report given the incredible mishandling of the situation. "Imran Narejo, an official of the PIA Pilots Association, said Gul was a seasoned pilot with 18,000 hours of experience including over 4,000 hours in the A320." https://english.kyodonews.net/news/2020/05/9616e4079ce1-at-least-92-killed-in-plane-crash-in-pakistans-karachi.html https://english.kyodonews.net/news/2020/05/9616e4079ce1-at-l...

ominous_prime 6y ago
The report corroborates the witness, video, ADS-B, and ATC recordings we had hours after the crash. It adds more details we couldn’t determine at that time, but otherwise it looks to be quite accurate
m3h 6y ago
In Pakistan, there is a culture of becoming overconfident and ignorant of the rules in the airline industry as the pilots age. This was also noted by the Aviation minister when he presented the PIA crash report to the assembly. It should be noted that two of the previous large crashes involving an Airblue and a Bhoja airplane were both concluded to be pilot error with the report pointing to overconfidence and negative attitude in cockpit, in addition to lack of regards for regulations for air safety and lack of training as well.
- sidewndr46 6y ago
  While I have no doubt this is true of Pakistan, it is true of many people who gain experience in a culture regardless of their age. A while back some US Air Force pilots landed a B-1 bomber on Diego Garcia. The entire flight and the landing was flawless, other than the part where they landed with the gear in the retracted position. The report on the incidents finding was they simply went right past the item on the checklist like it never happened.
- linuxftw 6y ago
  This is indicative of a systemic culture of rule breaking. This is common in all government run systems. "The system is too arduous, doesn't reflect the 'real world.' We know better than the system, we know what really matters." Eventually you have a bunch of John Waynes playing fast and loose with the rules, eventually they become emboldened, and since the government is famously bad at policing itself, these attitudes are pervasive. This happens at the highest levels, even. Consider Hillary Clinton and the communication of classified (and information that should have been considered classified regardless of markings) via her primary email server. It's a pervasive culture of rule breaking.

AareyBaba 6y ago

This channel has done an excellent job of analyzing the available data [1] https://youtu.be/76osJupy_P8?t=16 https://youtu.be/76osJupy_P8?t=16 and the latest [2] https://youtu.be/xu69Lkf9BYc?t=8 https://youtu.be/xu69Lkf9BYc?t=8